Island



UNITED STATES PATENT FFIcE.

ELIJAH I3. BENIIAM, OF PROVIDENCE, RHODE ISLAND.

PITMAN.

SPECIFICATION forming part of Letters Patent No. 395,206, dated December 25, 1888.

Application filed March 22, 1888.

T0 a/ZZ whom it may concern-.-

Be it known that I, ELIJAH ll. BENHAM, a citizen of the United States of America, residing at Providence, in'the county of Providence and State of Rhode Island, have invented new and useful Improvements in Iitman and Crank Connections, of which the following is a specification.

This invention relates to an improved form of connection between a pitman or connect ing rod and a crank or wrist pin or other similar part of a machine partimilarly applicable for use where several pitman-rods converge to and are engaged with a common crank-pin, as in multiple-cylinder rotary engines, the object thereof being to so form and connect the several pitinan-rods to the crankpin that each mayhave a considerable length of bearing around the periphery of said pin, whereby the said bearing portions of the several pitman-rods will require and occupy but little lengt-hwise-extended area on the periphery of the crank-pin, securing an easier, steadier, and more accurate and durable connection than heretofore; and the invention consists in the peculiar formation of each of the several pitman-rods, and in the combination, with the severalof the said pitmanrods and the crank-pin, of devices for securing the connection between said pitman-rods and cranlcpin, all substantially as will here matter more fully appear, and be set forth in the claims.

In the accom mnying sheet of drmvings the present invention is illustrated as applied in connection with a multiple-cylinder rotary engine or motor, the cylinders of which radiate from a common center, Figure 1 being a central vertical section through the cylinderhead thereof. Fig. 2 is a partial crosssection on the line 41, .13, Fig. 1; and Fig. 3 is a view of a pitman-roiilformed in accordance with this invention.

In the drawings, A represents the cylinderhead of a 1nultipie-cylinder rotary engine of the character described, comprising eight cylinders, the cutting-plane of the section here given passing through two cylinders, 5 G, radially and oppositely disposed in relation to the axial line of the main shaft B, said cylinders having their axes in a plane intersect- Serial No. 268,156. (No model.)

ing the crank-pin D, carried by said main shaft, transversely and midway of its length.

E represents the pistons in said cylinders, and each piston of the several cylinders has a pitman-rod, G, axially connected thereto in any usual or approved manner.

Each pitman-rod is provided at its end opposite from its piston with a foot, (Z, having its inner or heel end, f, when in place about the crank-pin, in the central transverse plane of said crank-pin, which is also coincident with the axes of the cylinders, and the alternate pitman-rods are disposed on the crankpin to project by their feet from. said central portion thereof to its outer end forinstance, toward the rightand the relatively intermediate pitman-rods are arranged to project by their feet from said common central portion of the crank-pin toward the opposite end or to the left. The extent of the length of the arc-formed bearing-surface of each foot is determined by the number of such pitmanrods to be employed about and upon a single erank-pinas, for instance, as shown, where eight pitman-rods are employed, the feet of four thereof about one end portion of the crank-pin and the feet of the other four about the other end portion of said crankpin. The curved bearing-surface of each foot is an arc embracing a little less than onequarter of a circle, so that the feet of four pitman'ro ds may be disposed about the periphery of one end portion of the crank-pin, allowing a little clearance between the feet to enable the edges of said feet to move slightly toward and away from each other under varying directions of the piston forces in different portions of a stroke, and in Fig. 2 the described disposition of the eight pitmanrods about one crank pin is particularly shown. The said ,rods, designated by 9, have their feet extendii'ig to the right, while the relatively intermediate rods have their feet extending to the left.

Each pitman-rod extends perpendicularly from its foot, its one side, m, being in the plane of the heel end f of said foot for a certain distance, when it is widened, as at n, for

increased strength, and to enable its inner end to be connected concentrically about the axial portion of the piston.

The angular feet of each series of pitmanrods are confined in place by a sleeve or collar, M, of an internal size to embrace the outer sides of said feet, and both of said collars at their inner end portions have flanges or rightangled lugs p, which lie by their sides against the outer sides of the pitman-rods, and upon the outer sides of one or more pitman-rods of each series-as, for instance, on the two diametrically opposite to each other-a segmental plate, Q, rabbeted at its inner side in an arc line, as at q, is hung by and upon a bolt, 2, which passes through the segmental plate which is at one side of ihe central transverse portion of the crank-pin overlying the flange of one ring, M, to and through the similar segmental plate, Q, overlying the flange of the ring M at the other side of the central trans verse portion of the crank-pin, whereby the said rings are held to their confining positions upon the pitman-rod feet for their retention in place about the crank-pin. Instead of supporting two segmental plates, Q, upon a single pitman-rod, one to overlie each flanged ring M, one of said plates Q may be hung upon one pitman for its engagement with one flanged ring, while another thereof may be hung upon another pitman for an engagement with the other flanged ring, and, in practice, more or less of the said segmental plates may be employed, as desired, although two for each ring M are generally sufficient; and where two segmental plates are supported from a single pitman, as shown in Fig. 1, a washer, 1', is disposed about the bolt 15 between the side of the pitman and the one of said plates to add rigidity and support to the parts.

Preferably, and as seen in Fig. 1, each pitman-rod foot (I, as to its thickness, tapers outwardly on its side opposite its arc-shaped crank-bearing face, and each of the rings V is also made with a corresponding inner flaring or tapering periphery, whereby the wear upon the arc-shaped bearing-faces about and upon the crank-pin maybe taken up by drawing the rings M inwardly on the bolts, turning the nuts thereon.

As shown in the drawings, the crank-pin D is bushed with a loose friction-sleeve, .I, the same constituting a part of the crank-pin, although the same may in some instances be dispensed with without departing from the present invention.

W'hat I claim as my invention is- 1. In a multiple cylinder rotary engine comprising a series of radial cylinders, a main shaft, B, having the crank or wrist pin, and a piston for each of said .radial cylinders, the combination, with said crank or wrist pin, of a series of pitman-rods each connected with a piston and each consisting of the leg POllTlOl'l, and the segmental foot formed thereupon and extending from one side thereof, provided with an arcsliaped bearing-surface, a portion of said series of pitman-rods being arranged with their feet extending from the central portion of said cranlcpin toward one end thereof, and the other portion of said series of pitmanrods bein arranged with their feet extending from said central portion of said crank-pin to ward the other end thereof, and independent collars surrounding the said feet of each series, substantially as described.

2. In a multiple cylinder rotary engine comprising a series of radial cylinders, a main shaft, 13, having a crank or wrist pin, and a piston for each of said radial cylinders, the combination, with said crank or wrist pin, of a sleeve thereon, and a series of pitman-rods each connected with a piston and each con sisting of the leg portion and the segmental foot formed thereupon and extending from one side thereof, provided with an arc-shaped bearing-surface, a portion of said series of pitman-rods being arranged with their feet extending from the central portion of said crank-pin toward one end thereof, and the other series of pitman-rods being arranged with their feet extending from said central portion of said crank-pin toward the other end thereof, and independent collars surrounding each series of feet, for the purpose described.

3. In a multiple cylinder rotary engine comprising a series of radial cylinders, a main shaft, B, having the crank or wrist pin, and a piston for each of said radial cylinders, the combination, with said crank or wrist pin, of a series of pitman-rods each connected with a piston and each consisting of the leg portion and the foot formed thereon andextending from one side thereof, provided with an areshaped bearing surface and tapering outwardly as to its thickness, a portion of said series of pitman -rods being arranged with their feet extending from the central portion of said crank-pin toward one end thereof, and the other portion of said series of pitman-rods bein arranged with their feet extending from said central portion of said crank-pin toward the other end thereof, and collars provided with a tapering internal periphery surrounding said feet of each series, substantially as "and for the purpose described.

4. In a multiple cylinder rotary engine comprising a series of radial cylinders, amain shaft, B, having the crank or wrist pin, and a piston for each of said radial cylinders, the combination, with said crank or wrist pin, of a series of pitman-rods, each connected with a piston and each consisting of the leg portion and the segmental foot formed thereon and extending from one side thereof, provided with an arc-shaped bearing-surface, the said leg portion having its one or outer side for a portion of its length in the plane of the heel end thereof and for a portion of its length widened to extend across said plane, a portion of said series of pitman-rods being arranged with their feet extending from the central portion of said crank-pin toward one end thereof and the other portion of said series of pitman-rods being arranged with their feet extending from said central portion of said crank-pin toward the other end thereof, and independent collars surrounding the said feet of each series, for the purpose desciibed.

5. In a nuiltiple-cylinder rotary en gine comprising a series of radial cylinders, a main shaft, 13, having the crank or Wrist pin, and a piston for each of said cylinders, the combination, with said crank or wrist pin, of a series of pitnian-rods, each connected with a piston and each consisting of the leg portion and the foot formed thereupon, and extending from one side thereof, provided with an areshaped bearing-surface, a portion of said series of pitman-rods being arranged with the feet extending from the central portion of said crank-pin toward one end thereof, and the other portion of said series of pitmanrods being arranged with the feet extendin from said central portion of said crank-pin to the other end thereof, and the collars surrounding each series of feet, each collar provided with the flange p, and segmental plates Q,overlying said collar-flanges, each hung upon one of said pitman-rods, substantially as and for the purpose described.

(3. In a multiple cylinder rotary engine comprising a series of radial cylinders, a main shaft, 13, having the crank or wrist pin, and a piston for each of said cylinders, the combination, with said crank or wrist pin, of a sleeve, J, thereon, and a series of pitman-rods, each connected with a piston and each consisting of the leg portion and the foot formed thereupon and extending from one side thereof, provided with an arc-shaped hearing-surface and tapering outwardly as to its thickness, and the said leg portion having its outer side for a portion of its length in the plane of the heel end thereof, and for a portion of its length widened to extend across such plane, a portion of said series of pitman--rods being arranged with their feet extending from the central portion of said crank-pin toward. one end thereof, and the other portion of said series of pitman-rods being arranged with their feet extending from said central portion. of said crank-pin toward the other end thereof, the collars M M, one of which surrounds each series of feet, having tapering internal peripheries and provided with the flanges p, and rabbeted segmental plates Q, overlying said collar-flanges, and the bolts passing through said segmental plates and the pi'tmaurods, all. substantially as and for the purpose described.

7. The coinbination,\vitl1 the crank-pin D, of a series of pitinan-rods, each consisting of the leg portion and the foot formed thereupon and extending from one side thereof, provided with an arc-shaped bearing-surface, a portion of said series of pitman-rods being arranged with'the feet extending from the central portion of said crank-pin toward one end thereof, and the other portion of said series of pitman-rods arranged with the feet extending from said central portion of said crank-pin toward the other end thereof, the collars M, surrounding each series of feet, each collar provided with the flange Q), the segmental plates Q. Q, hung in pairs on the bolt 1 of one of the pitman-rods an d. overlying said ring-flanges, and the washers r, suhstantially as described.

ELIJAII l3. BENHAM. Vitnesses:

WM. S. BELLows, G. M. CHAMBERLAIN. 

